Various bicyclo compounds are known. For example, copending U.S. patent application Ser. No. 16,548 filed Mar. 1, 1979, is directed to 13-oxabicyclo[10.3.0]-pentadecane. Applicants have surprisingly prepared 13,15-dioxabicyclo[10.5.0]heptadecanes and have found them to be useful as perfumery agents.